Disclosed here in the present specification are a group of inventions so linked as to form a single general inventive concept, with respect to various uses of specific N-long-chain acyl neutral amino acid esters and specific N-long-chain acyl acidic amino acid diesters as active ingredients of cosmetic compositions.
A first invention of such a group of inventions (hereinafter, referred to as xe2x80x9cthe first inventionxe2x80x9d) relates to an oily ingredient of cosmetics which is formed of a specific N-long-chain acyl neutral amino acid ester, and a cosmetic composition characterized by containing the same. More specifically, it relates to an oily material(or oily ingredient) of cosmetics which is formed of an N-long-chain acyl neutral amino acid ester where the hydrocarbon group of the alcoholic moiety is a straight-chain or branched-chain, saturated or unsaturated hydrocarbon group having from 1 to 10 carbon atoms. (In other words, the hydrocarbon residue of the alcoholic moiety constituting such N-long-chain acyl neutral amino acid ester is a straight-chain or branched-chain, saturated or unsaturated hydrocarbon group with 1 to 10 carbon atoms.) It also relates to a cosmetic composition characterized by containing the same.
A second invention of such a group of inventions (hereinafter, referred to as xe2x80x9cthe second inventionxe2x80x9d) relates to an ultraviolet ray-absorbing composition. More specifically, it relates to an ultraviolet ray-absorbing composition characterized by containing an ultraviolet rays absorbent (i.e., an ultraviolet rays absorbing agent) and an N-long-chain acyl neutral amino acid ester or/and an N-long-chain acyl acidic amino acid diester as active ingredient(s). This ultraviolet ray-absorbing composition includes, as an embodiment thereof, a cosmetic composition.
And, a third invention of such a group of inventions (hereinafter, referred to as xe2x80x9cthe third inventionxe2x80x9d) relates to an inorganic pigment composition. More specifically, it relates to an inorganic pigment composition characterized by containing an inorganic pigment and an N-long-chain acyl neutral amino acid ester or/and an N-long-chain acyl acidic amino acid diester as active ingredient(s). This inorganic pigment composition includes, as an embodiment thereof, a cosmetic composition.
First, the background art on the first invention is as follows.
In cosmetic compositions, an oily material is widely used as a binder for the components, an emollient or the like, or for providing a hair conditioning property. As an oily material for a cosmetic composition, mineral oils such as liquid paraffin and the like, and fatty acid esters such as IPM (isopropyl myristate) and IPP (isopropyl palmitate) have been widely used so far.
Further, an example in which amino acid derivatives are used as an oily material has been known. For example, Japnese patent publication (kokoku) No. 12908/1979 discloses an ester of an N-long-chain acyl neutral amino acid and a higher alcohol having from 12 to 30 carbon atoms as an oil-soluble surfactant which is suitable in the field of fragrances.
However, these oily materials for cosmetics have involved problems that the oily materials when formulated in cosmetic compositions may impair the feeling upon use of the cosmetic composition owing to an unpleasant oily feeling or stickiness peculiar to such oily material. Further, a hair conditioning effect has not been satisfactory. Accordingly, an oily material for cosmetics which is better in these points has been in great demand.
By the way, as an N-long-chain acyl neutral amino acid ester, an amino acid ester with a long-chain alcohol has been known as described in the Jap. pat. Publn. (kokoku) No. 12908/1979. However, with respect to an amino acid ester with a shorter-chain alcohol, examples in which it is actually synthesized and studied for use in cosmetics have been hardly known. As a specific example, it is only disclosed on page 167, lower column to page 168, left upper column of the Jap. pat. Publn. (kokoku) No. 129078/1979 that N-2-ethylhexanoyl-N-methyl-xcex2-alanine.methyl ester is tested and its compatibility with an oily solvent is poor. Thus, an ester of an N-long-chain acyl neutral amino acid and a short-chain alcohol has not been used at all as an oily material for cosmetics.
However, in recent years, owing to the advancement of a blending technique, an emulsifying equipment and the like, the problem of such compatibility is rather considered less serious, and an important subject is how to satisfy consumers"" various needs and higher levels of needs.
Accordingly, it is an object of the invention to provide an oily material for cosmetics which is improved in an oily feeling or stickiness, which has an excellent feeling upon use of a cosmetic composition and also in a hair conditioning effect, and further to provide a cosmetic composition containing the same.
Next, the background concerning the second invention is as follows.
Ultraviolet rays are known to give various changes to the skin. In the field of dermatology, ultraviolet rays are classified into long-wave ultraviolet ray (400 to 320 nm), medium-wave ultraviolet ray (320 to 290 nm) and short-wave ultraviolet ray, which are called UV-A, UV-B and UV-C in this order, respectively. Of these, UV-C is absorbed in the ozone layer, and scarcely reaches the earth. Further, with respect to UV-B, it is known that when the skin is irradiated with more than its certain amount, an erythema or a blister is formed or pigmentation occurs. Meanwhile, it has been so far said that UV-A does not change the skin so much. However, it has recently been found through an electron microscope or from a histological evaluation that UV-A changes the elastic fibers in the blood vessel wall or the connective tissue, or damages the sensitive skin. Moreover, it has been reported that UV-A accelerates the activity of UV-B (J. Invest. Derm. 59 (6), 416 (1973)). Accordingly, it is important to cut UV-A. For these reasons, cosmetics or skin medicines for external application often contain an ultraviolet rays absorbent (UV absorbent) as an ultraviolet ray cutting agent (UV cutting agent).
As UV-A absorbents which have been lately highlighted, for example, 4-t-butyl-4xe2x80x2-methoxybenzoylmethane and 2-ethylhexyl dimethoxybenzylidenedioxoimidazolidinepropionate (with respect to the latter, see Japanese patent application laid-open (kokai) No. 101371/1988) can be mentioned. These are solids which are sparingly soluble in water and oil(with respect to the former, see Jap. pat. appln. Laid-open (kokai) No. 291019/1997). The sparingly-soluble UV absorbents involve problems that sufficient amounts thereof cannot be incorporated in cosmetics or the like, and when these UV absorbents are once incorporated, crystals thereof are precipitated in cosmetics or skin medicines for external application during the storage, i.e., the stability thereof is therefore poor. Especially in the latter case, appropriate solvents are limited in their type.
The ultraviolet rays are harmful to (the skin of) humans. Moreover, of plastics, emulsion paints, oil paints, coating agents and the like, there are some components thereof which undergo degradation by ultraviolet rays, and deterioration is prevented by incorporating an ultraviolet ray absorbent in such products. The foregoing problems associated with the sparingly-soluble UV absorbent also occur with respect to the use in such plastics and the like other than the skin of humans.
By the way, an oil is incorporated into cosmetics containing a UV absorbent in order to prevent the UV absorbent from flowing down due to sweat or water. However, there is a problem that when an oil is incorporated into cosmetics or skin medicines for external application, stickiness is provided.
Accordingly, under these circumstances of the conventional art, it is an object of the present invention is to provide an ultraviolet rays absorbing composition usable as a cosmetic composition, which is excellent in the lack of a stickiness, which is less irritates the skin, and in which a sparingly-soluble UV absorbent, when used, can stably be incorporated at a high concentration
And finally, the background concerning the third invention is as follows.
An inorganic pigment is, as well known, ordinarily used in cosmetics, paints, resins, ink, rubbers, pencils and the like. For example, in cosmetics, an inorganic pigment is incorporated to impart, to products, characteristics such as extensibility, adhesion, film-strength power and the like, to maintain forms of products or to color the same.
When an inorganic pigment is used for these purposes, it is required that the inorganic pigment is uniformly dispersed in a composition and a composition free from unevenness of a color or the like and having high dispersion stability is provided. However, since inorganic pigments are less compatible with an oil, it is difficult to obtain a better dispersion state because of the influence of the oily material in the composition. For example, even when an oily material having a relatively high polarity, such as lanoline, isopropyl myristate, a fatty acid higher alcohol ester or the like is used in cosmetics, it is difficult to obtain a satisfactory dispersibility.
Thus, in a composition containing an oily material (i.e., oily ingredient) and an inorganic pigment, there are problems that a relatively large amount of an oily material has to be added for dispersing the inorganic pigment and that when an inorganic pigment is used in cosmetics, for example, the feeling upon use is notably decreased because of an unpleasant oily feeling or stickiness peculiar to the oily material.
Accordingly, in such background of the conventional art, it is an object of the present invention to provide an inorganic pigment composition usable as a cosmetic composition which is excellent in dispersibility (stability) of an inorganic pigment, which is less irritative to the skin, when used in cosmetics, and which exhibits a good feeling upon use.
In view of the background of the first invention, the present inventors have assiduously conducted investigations, and has consequently found that an N-long-chain acyl neutral amino acid ester where the hydrocarbon group of the alcohol constituting the ester is a hydrocarbon group having from 1 to 10 carbon atoms, has a dry or clean feeling although it is an oily material, exhibits an improved feeling upon use onto the skin, such as extensibility, adaptability, smoothness or the like in addition to the clean feeling, and is further excellent in hair conditioning effect. These findings have led to the completion of the present invention.
Accordingly, the first invention relates to an oily material usable as a cosmetic composition which is formed of an N-long-chain acyl neutral amino acid ester containing an acyl group having from 6 to 22 carbon atoms, where the hydrocarbon group of the alcohol constituting the ester is a hydrocarbon group having from 1 to 10 carbon atoms. Further, the invention relates to a cosmetic composition characterized by containing such oily material.
Now, the invention will be described in greater detail below.
The long-chain acyl group of an N-long-chain acyl neutral amino acid ester of the present invention is a straight-chain or branched-chain, saturated or unsaturated acyl group having from 6 to 22 carbon atoms. Examples thereof include those acyl groups which can be derived from capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, linoleic acid, linolenic acid, oleic acid, isostearic acid, 2-ethylhexanoic acid, coconut oil fatty acid, tallow fatty acid, hardened tallow fatty acid, palm kernel oil fatty acid, and the like. Preferable examples of the acyl group include a caproyl group, a lauroyl group, a myristoyl group, a palmitoyl group, a stearoyl group, a behenoyl group, a coconut oil fatty acid acyl group, a hardened tallow fatty acid acyl group and the like.
Further, examples of the neutral amino acids constituting the neutral amino acid moiety include neutral amino acids such as glycine, alanine, valine, leucine, isoleucine, serine, threonine, proline, xcex2-alanine, aminobutyric acid, sarcosine, N-methyl-xcex2-alanine and the like. Preferable are glycine, alanine, valine, leucine, isoleucine, xcex2-alanine, xcex1-aminobutyric acid, xcex3-aminobutyric acid, sarcosine and N-methyl-xcex2-alanine. More preferable are glycine, alanine, xcex2-alanine, xcex1-aminobutyric acid, xcex3-aminobutyric acid, sarcosine and N-methyl-xcex2-alanine. Furthermore preferable are sarcosine, alanine, glycine and N-methyl-xcex2-alanine. Especially preferable are N-alkyl neutral amino acids. Most preferable are sarcosine and N-methyl-xcex2-alanine. These amino acids may be optically active compounds or racemic compounds.
And, the hydrocarbon group of the alcohol constituting the ester is a branched-chain or straight-chain alkyl or alkenyl group having from 1 to 10 carbon atoms. The alkyl group is preferable. Examples thereof include hydrocarbon groups which can be derived from ethanol, propanol, isopropanol, butanol, t-butanol, isobutanol, 3-methyl-1-butanol, 2-methyl-1-butanol, fusel oil, pentanol, hexanol, cyclohexanol, octanol, 2-ethylhexanol and decanol. A methyl ester having 1 carbon atom is undesirable because it means that methanol is used as a starting material.
Further, a branched-chain or straight-chain alkyl group having from 2 to 8 carbon atoms is preferable from the standpoint of feeling upon use. Especially, a branched-chain or straight-chain alkyl group having from 2 to 5 carbon atoms is preferable because a dry or clean feeling is excellent and the effects of the present invention are exhibited more satisfactorily. Still further, a branched-chain alkyl group having from 3 to 5 carbon atoms is preferable from the aspect of the stability against hydrolysis in addition to the feeling upon use and the like. Examples thereof include an isopropyl group, a t-butyl group, an isobutyl group and the like. Of these, an isopropyl group is most preferable.
When preferable examples of the N-long-chain acyl neutral amino acid ester of the present invention are represented by the general formula, those represented by Formula (1) below can be mentioned. 
wherein
R1 represents a branched-chain or straight-chain alkyl or alkenyl group having from 5 to 21 carbon atoms,
R2 represents a hydrogen atom or a straight-chain or branched-chain alkyl group having from 1 to 3 carbon atoms,
R3 represents a hydrogen atom or a straight-chain or branched-chain alkyl group having from 1 to 4 carbon atoms,
R4 represents a branched-chain or straight-chain alkyl or alkenyl group having from 1 to 10 carbon atoms, and
n is an integer of from 0 to 2.
In Formula (1), preferable examples of the acyl group (R1xe2x80x94COxe2x80x94) and the hydrocarbon group R4 of the alcohol constituting the ester have been mentioned above. Preferable examples of the neutral amino acid moiety have also been mentioned above. As R2 is more preferable a hydrogen atom or a methyl group, and most preferably a methyl group. As R3is preferable a hydrogen atom or a methyl group, and most preferably a hydrogen atom. As n is more preferable an integer of 0 or 1.
In this connection, it is to be noted that those N-long-chain acyl neutral amino acid esters which are represented by Formula (1) are novel compounds.
The N-long-chain acyl neutral amino acid ester of the present invention can be obtained by, for example, esterifying an N-long-chain acyl neutral amino acid and an alcohol through heat-dehydrocondensation under atmospheric pressure or reduced pressure. Further, it can also be obtained by an azeotropic dehydrocondensation reaction using a solvent such as toluene or the like (see Synthesis Examples 5, 6 and the like to be described later) or by transesterification reaction. An N-long-chain acyl neutral amino acid or an alcohol to be used to synithesize the N-long-chain acyl neutral amino acid ester are not necessarily single compounds, and they may be a mixture of N-long-chain acyl neutral amino acids containing different acyl groups and/or neutral amino acids and a mixture of alcohols which are different in the chain length or the like.
The resulting N-long-chain acyl neutral amino acid ester can be used after purification by a known method which those skilled in the art commonly use, such as distillation, extraction, chromatography or the like. Incidentally, with respect to the N-long-chain acyl neutral amino acid and its salt which are starting materials in the production, the alcohol and the like acceptable in a cosmetic composition, and further, the starting neutral amino acid and the like and by-product fatty acids and the like which may accompany the N-long-chain acyl neutral amino acid and its salt, they are ordinarily used in the cosmetic composition, and therefore, may be contained in the N-long-chain acyl neutral amino acid ester unless the effects of the present invention are impaired.
By the way, N-long-chain acyl neutral amino acid can be produced by a known method, for example, the so-called Schotten-Bauman reaction (see Japanese patent publication (kokoku) No. 38681/1976 and the like) in which a long-chain fatty acid halide is reacted with an amino acid in the presence of a basic catalyst.
The oily material for cosmetic compositions of the present invention can be used as an oily ingredient for various cosmetic compositions such as skin care product, hair care product and the like, and it can be formed into cosmetic compositions of the present invention. As such cosmetic composition can be mentioned various cosmetic compositions, such as washing cream, washing foam, cleansing cream, massage cream, cold cream, moisture cream, milky lotion, lotion, hand cream, pack, men""s skin care product, foundation, lipstick, press powder, eye shadow, hair oil or cream in stick from, hair liquid, setting lotion, permanent wave liquid, hair cream, hair lotion, hair mousse, shampoo, hair rinse, hair conditioner, body shampoo, solid detergent, liquid detergent, antiperspirant, after-shave cream, anti-sunburn cream, anti-sunburn oil, bath product, hair dye and the like. The form of the cosmetic compositions is not particularly limited. Any formmay be taken. Examples thereof include an emulsion form, a solution form, a soluble form, a powder dispersion form, a water-oil two-layer form, a water-oil-powder three-layer form and the like.
The cosmetic composition of the present invention can contain any other oily materials or ingredients which are usable in cosmetics unless the effects of the present invention are impaired. Examples of such materials can include oily materials derived from animals and plants, such as saturated or unsaturated fatty acids and higher alcohols obtained therefrom, squalane, castor oil and derivatives thereof, bees wax, lanolines including liquid and purified lanolines and derivatives thereof, cholesterol and derivatives thereof, academian nut oil, jojoba oil, carnauba wax, sesame oil, cocoa oil, palm oil, mink oil, Japan wax, candelilla wax, whale oil and the like; oily materials derived from petroleum and mineral, such as paraffin, microcrystalline wax, liquid paraffin, vaseline, ceresine and the like; silicones, for example, silicone polymers such as methylpolysiloxane, polyoxyethylene.methylpolysiloxane, polyoxypropylene.methylpolyoxysiloxane, poly(oxyethylene, oxypropylene).methylpolysiloxane, methylphenylpolysiloxane, fatty acid-modified polysiloxane, fatty alcohol-modified polysiloxane, amino acid-modified polysiloxane and the like; a resin acid; a fatty acid ester; ketones and the like. Since the N-acyl neutral amino acid ester of the present invention is also effective for improving stickiness and the like of the other oily materials, the effects of the present invention can satisfactorily be exhibited also in cosmetic compositions containing such other ordinary oily materials.
Further, the cosmetic composition of the present invention can contain one or more surfactants insofar as the effects of the present invention are not impaired. Examples thereof include anionic surfactants such as, e.g., N-long-chain acyl amino acid salts such as N-long-chain acyl acidic amino acid salts and N-long-chain acyl neutral amino acid salts, N-long-chain fatty acid acyl-N-methyltaurine salts, alkyl sulfates, and alkylene oxide adducts thereof, fatty acid amide ether sulfates, fatty acid metal salts and weak base salts, sulfosuccinic acid-type surfactants, alkyl phosphates, and alkylene oxide adducts thereof, and alkyl ether carboxylic acids; nonionic surfactants such as, e.g., ether-type surfactants such as glycerol ethers, and alkylene oxide adducts thereof and the like, ester-type surfactants such as glycerol esters, and alkylene oxide adducts thereof and the like, ether ester-type surfactants such as sorbitan esters, and alkylene oxide adducts thereof and the like, ester-type surfactants such as polyoxyalkylene fatty acid esters, glycerol esters, fatty acid polyglycerol esters, sorbitan esters, sucrose fatty acid esters and the like, alkyl glycosides, nitrogen-containing nonionic surfactants such as hardened castor oil pyroglutamic acid diesters, and ethylene oxide adducts thereof, fatty acid alkanol amides and the like; cationic surfactants, for example, aliphatic amine salts such as alkylammonium chlorides, dialkylammonium chlorides and the like, and quaternary ammonium salts thereof, aromatic quaternary ammonium salts such as benzalkonium salts and the like, and fatty acid acylarginine esters; and amphoteric surfactants, for example, betaine-type surfactants such as carboxybetaine and the like, aminocarboxylic acid-type surfactants, and imidazoline-type surfactants.
Moreover, the cosmetic composition of the invention can contain, other than those surfactants mentioned above, various additives which are ordinarily used in a cosmetic composition unless the effects of the invention are impaired. Examples thereof include amino acids such as glycine, alanine, serine, threonine, arginine, glutamic acid, aspartic acid, leucine, valine and the like; polyhydric alcohols such as glycerol, ethylene glycol, 1,3-butylene glycol, propylene glycol, isoprene glycol and the like; water-soluble high-molecular compounds such as polyamino acids including polyglutamic acid and polyaspartic acid, and salts thereof, polyethylene glycol, gum arabic, alginates, xanthane gum, hyaluronic acid, hyaluronates, chitin, chitosan, water-soluble chitin, carboxyvinyl polymer, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyltrimethylammonium chloride, poly-(dimethylmethylenepiperidium chloride), polyvinylpyrolidone derivative quaternary ammonium salt, cationic protein, collagen hydrolyzate, and derivatives thereof, acylated protein, polyglycerol and the like; sugar alcohols such as mannitol and the like, and alkylene oxide adducts thereof; and lower alcohols such as ethanol, propanol and the like. Further, extracts of animals and plants, nucleic acids, vitamins, enzymes, anti-inflammatory agents, disinfectants, antiseptics, antioxidants, ultraviolet rays absorbents, chelating agents, antiperspirants, pigments, coloring matters, oxidation colors, organic and inorganic powders, pH modifiers, pearlescent agents, wetting agents and the like can also be contained.
The amount of an N-long-chain acyl neutral amino acid ester of the present invention to be incorporated into a cosmetic composition, varies depending on the form of a product, and it is not particularly limited. It is commonly used in the range of 0.01% by weight or more. The preferable range is between 0.1 and 50% by weight in case of a skin cosmetic composition. It can preferably be between 0.1 and 30% by weight in case of a hair cosmetic composition.
Further, in view of the background on the second invention, the present inventors have assiduously conducted investigations, and have consequently found that the above-mentioned problems can be solved by, when incorporating a UV absorbent into cosmetics or the like, using a specific N-long-chain acyl neutral amino acid ester or N-long-chain acyl acidic amino acid diester, together with the UV absorbent. These findings have led to the completion of the invention.
Accordingly, the second invention relates to an ultraviolet ray-absorbing composition characterized by containing, as active ingredients, an ultraviolet ray absorbent, and (A) an N-long-chain acyl neutral amino acid ester containing a straight-chain or branched-chain, saturated or unsaturated acyl group having from 6 to 22 carbon atoms, where the hydrocarbon group of the alcohol constituting the ester is a straight-chain or branched-chain, saturated or unsaturated hydrocarbon group having from 1 to 10 carbon atoms or/and (B) an N-long-chain acyl acidic amino acid diester containing a straight-chain or branched-chain, saturated or unsaturated acyl group having from 6 to 22 carbon atoms, where the hydrocarbon group of the alcohol constituting the ester is a straight-chain or branched-chain, saturated or unsaturated hydrocarbon group having from 1 to 10 carbon atoms.
Incidentally, the two types of the esters mentioned above are less irritative to the skin and can be an excellent oily material (oily agent) of cosmetic composition or the like.
Now, the second invention will be described in greater detail below.
First, UV absorbents, one of the ingredients of the ultraviolet ray-absorbing composition of the present invention will be described.
As UV absorbents for cosmetics or the like, a large number of ultraviolet ray absorbents have been developed. Examples thereof include benzophenone-type ultraviolet ray absorbents such as 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone 5-sulfonic acid, sodium 2-hydroxy-4-methoxybenzophenone-5-sulfonate, dihydroxydimethoxybenzophenone, sodium dihydroxydimethoxybenzophenonesulfonate, 2,4-dihydroxybenzophenone, tetrahydroxybenzophenone and the like; para-aminobenzoic acid-type ultraviolet ray absorbents such as para-aminobenzoic acid (PABA), ethyl para-aminobenzoate, glyceryl para-aminobenzoate, amyl para-dimethylaminobenzoate, octyl para-dimethylaminobenzoate and the like; cinnamic acid-type ultraviolet ray absorbents such as ethyl para-methoxycinnamate, isopropyl para-methoxycinnamate, octyl para-methoxycinnamate, 2-ethoxyethyl para-methoxycinnamate, sodium para-methoxycinnamate, potassium para-methoxycinnamate, mono-2-ethylhexanoic acid glyceryl para-methoxycinnamate; and salicylic acid-type ultraviolet ray absorbents such as octyl salicylate, phenyl salicylate, homomethyl salicylate, dipropylene glycol salicylate, ethylene glycol salicylate, myristyl salicylate, methyl salicylate and the like, as well as urocanic acid, ethyl urocanate, 4-t-butyl-4xe2x80x2-methoxydibenzoylmethane (xe2x80x9cParsolxe2x80x9d ex Givaudan), 2-ethylhexyl dimethoxybenzylidenedioxoimidazolidinepropionate (see the above-mentioned Japanese patent application laid-open (kokai) No. 101371/1988), (2xe2x80x2-hydroxy-5xe2x80x2-methylphenyl)benzotriazole, methyl anthranylate and the like.
By the way, 4-t-butyl-4-methoxybenzoylmethane and 2-ethylhexyl dimethoxybenzylidenedioxoimidazolidinepropionate which is a benzal hydantoin derivative, both mentioned above, are excellent as a UV-A absorbent. Especially, 2-ethylhexyl dimethoxybenzylidenedioxoimidazolidinepropionate is a derivative of tyrosine, an amino acid, and preferable from the aspect of safety. Further, it has maximum absorption in the vicinity of 344 nm, and is an ultraviolet ray absorbent having a high UV-A absorbability. It has been already marketed under a tradename xe2x80x9cSoft Shade DHxe2x80x9d (ex Ajinomoto co., Inc.).
These UV absorbents are, as described above, solids which are sparingly soluble both in water and oil, have a poor compatibility with cosmetic compositions, skin medicines for external application or the like, and crystals tend to be precipitated over the course of time. Thus, they have been deemed problematic. Especially, with respect to 2-ethylhexyl dimethoxybenzylidenedioxoimidazolidinepropionate, there have been no oily agents having an excellent dissolving power.
Next, the N-long-chain acyl neutral amino acid ester and the N-long-chain acyl acidic amino acid diester which are the other essential ingredient of the ultraviolet ray-absorbing composition of the present invention will be described.
First, the N-long-chain acyl neutral amino acid ester is exactly the same as the N-long-chain acyl neutral amino acid ester described above with respect to the first invention.
Then, the N-long-chain acyl acidic amino acid diester will be described in detail.
The long-chain acyl group of the N-long-chain acyl acidic amino acid diester of the present invention is the same as the long-chain acyl group of the N-long-chain acyl neutral amino acid ester described above, and preferable examples of the acyl group are the same as those described above.
Further, examples of the acidic amino acid constituting the acidic amino acid moiety include glutamic acid, aspartic acid and the like. Especially preferable is glutamic acid. These amino acids may be either optically active compounds or racemic compounds.
The hydrocarbon group of the alcohol constituting the ester is the same as that of the N-long-chain acyl neutral amino acid ester described earlier, and preferable examples thereof are also the same as those described earlier.
When preferable examples of the N-long-chain acyl acidic amino acid diester of the present invention are represented by a general formula, those represented by Formula (2) below can be mentioned. 
Wherein
R1 is the same as R1 in Formula (1),
R2 and R3 are, independently from each other, the same as R4 in Formula (1), and
n is an integer of 0 or 1.
The N-long-chain acyl acidic amino acid diester of the present invention can be obtained by, for example, esterifying an N-long-chain acyl acidic amino acid and an alcohol through heat-dehydrocondensation under atmospheric pressure or reduced pressure. Further, it can also be obtained by an azeotropic dehydrocondensation reaction using a solvent such as toluene or the like or by transesterification reaction. The N-long-chain acyl acidic amino acid and the alcohol to be used to obtain the N-long-chain acyl acidic amino acid diester are not necessarily single compounds, and they may be a mixture of N-long-chain acyl acidic amino acids containing different acyl groups and/or acidic amino acids and a mixture of alcohols which are different in the chain length or the like.
Incidentally, the N-long-chain acyl acidic amino acid can be produced by a known method such as the so-called Schotten-Baumann reaction (see Japanese patent publications (kokoku) Nos. 8685/1971, 35058/1973, 38681/1976 and the like) in which a long-chain fatty acid halide is reacted with an amino acid in the presence of a basic catalyst.
Of these N-long-chain acyl amino acid esters, the N-long-chain acyl neutral amino acid ester is more preferable in view of stickiness and solubility.
The simplest embodiment or form of the ultraviolet ray-absorbing composition of the present invention is a composition composed substantially of one or more of the ultraviolet ray absorbents explained above, and one or more of the N-long-chain acyl neutral amino acid esters explained above or/and one or more of the N-long-chain acyl acidic amino acid diesters explained above and it can be put into circulation in as such form.
The preparation of such composition is not particularly limited, nor difficult to do, and the composition can be prepared by an appropiate known method.
The amount of UV absorbent in the composition of this embodiment is usually between 0.01 and 50% by weight, preferably between 0.1 and 20% by weight, and especially preferably between 0.1 and 10% by weight. Further, needless to say, it is advisable that a sparingly-soluble UV absorbent is incorporated in such amount that crystals are not precipitated.
Further, a UV absorbent and an N-long-chain acyl neutral amino acid ester or/and an N-long-chain acyl acidic amino acid diester can be used in the form of a composition of the above-mentioned embodiment, or can be directly used without having been formed into a composition of such embodiment in advance, to prepare cosmetic compositions, skin medicines for external application, plastics, emulsion paints, oil paints, coating agents or the like. The thus-prepared cosmetic compositions and the like are, of course, a kind of the ultraviolet ray-absorbing composition of the present invention. When it is incorporated in cosmetic compositions or skin medicines for external application, the UV absorbent is used in an amount of up to 20% by weight based on the total amount of the final product.
The ultraviolet ray-absorbing composition of the present invention in the form of cosmetic compositions or the like can be prepared by a known method including starting materials, except that a UV absorbent and an N-long-chain acyl neutral amino acid ester or/and an N-long-chain acyl acidic amino acid diester are incorporated into the other starting materials in predetermined amounts.
When an ultraviolet ray-absorbing composition of the present invention is used as a cosmetic composition or skin medicines for external application, it can be one of various cosmetic compositions and skin medicines for external application such as creansing cream, massage cream, cold cream, moisture cream, milky lotion, lotion, hand cream, foundation, lipstick, press powder, eye shadow, hair oil or cream in stick form, hair liquid, setting lotion, haircream, hair lotion, hair mousse, anti-sunburn cream, antisunburn oil, an external pharmaceutical composition and the like. Further, the form thereof is not particularly limited, and any form will do. Examples thereof include an emulsion type, a solution type, a soluble type, a powder dispersion type, a water-oil two-layer type, a water-oil-powder three-layer type and the like.
When an ultraviolet ray-absorbing composition of the present invention is prepared into a cosmetic composition or a skin medicine for external application, some other oily materials can also be incorporated unless the effects of the present invention are impaired. Such oily materials are exactly the same as the other oily materials as described earlier, which can be incorporated in a cosmetic composition of the first invention.
Further, the cosmetic compositions and the skin medicines for external application according to the present invention, can contain one or more of various surfactants unless the effects of the present invention are impaired. Such surfactants are exactly the same as those as described earlier, which can be incorporated into a cosmetic composition of the first invention.
Still further, the cosmetic compositions and the skin medicines for external application according to the present invention can contain, other than those components mentioned above, various additives which are ordinarily used in a cosmetic composition unless the effects of the present invention are impaired. Such various additives are exactly the same as those as described earlier, which can be incorporated into the cosmetic composition of the first invention.
In view of the background concerning the third invention, the inventors have assiduously conducted investigations, and have consequently found that the above-mentioned problems can be solved by using, when an inorganic pigment is incorporated into cosmetic compositions or the like, a specific N-long-chain acyl neutral or acidic amino acid ester along therewith. These findings have led to the completion of the present invention.
Accordingly, the third invention relates to an inorganic pigment composition characterized by containing, as active ingredients, an inorganic pigment and (A) an N-long-chain acyl neutral amino acid ester containing a straight-chain or branched-chain, saturated or unsaturated acyl group having from 6 to 22 carbon atoms, where the hydrocarbon group of the alcohol constituting the ester is a straight-chain or branched-chain, saturated or unsaturated hydrocarbon group having from 1 to 10 carbon atoms or/and (B) an N-long-chain acyl acidic amino acid diester containing a straight-chain or branched-chain, saturated or unsaturated acyl group having from 6 to 22 carbon atoms, where the hydrocarbon group of the alcohol constituting the ester is a straight-chain or branched-chain, saturated or unsaturated hydrocarbon group having from 1 to carbon atoms.
Incidentally, these two types of the esters are less irritative to the skin, and can be an excellent oily material (oily agent) of a cosmetic composition or the like, as has been described.
Now, the third invention will be described in greater detail below.
First, powdery inorganic pigments, one of the ingredients of the inorganic pigment composition of the present invention will be described.
Examples of the inorganic pigment to be used in cosmetic compositions include titanium dioxide, zinc oxide, iron oxide (red iron oxide), iron titanate, xcex3-iron oxide, yellow iron oxide, loess, black iron oxide, carbon black, lower titanium oxide, mango violet, palto violet, chromium oxide, chromium hydroxide, cobalt titanate, ultramarine, Prussian blue, titanium oxide-coated mica, titanium oxide-coated bismuth oxychloride, titanium oxide-coated talc, colored titanium oxide-coated mica, bismuth oxychloride, fish scale flake, aluminum powder, copper powder, gold powder, mica, talc, kaolin, sericite, white mica, phlogopite, synthetic mica, lepidolite, biotite, lithia mica, vermiculite, calcium carbonate, magnesium carbonate, aluminum silicate, barium silicate, calcium silicate, magnesium silicate, strontium silicate, tungstic acid metal salt, silica, zeolite, barium sulfate, calcined calcium sulfate (calcined gypsum), calcium phosphate, fluorine apatite, hydroxyapatite, ceramic powder, metallic soap (zinc myristate, calcium palmitate, aluminum stearate and the like), boron nitride, photochromic pigment and the like. Further, an inorganic pigment surface-treated with a surface modifier or the like will do. Examples thereof include inorganic pigments coated with Nxcex5-lauroyl lysine, perfluoroalkyl phosphate diethanolamine, sodium metaphosphate, amino acid, acylated collagen, lecitin, metallic soap, acyl amino acid salt, silicone such as methylhydrogen polysiloxane or the like, polyacrylic acid, chitosan, nylon powder, color pigment or the like. Even an inorganic pigment of which the dispesibility has been improved through such surface treatment, the dispersibility can be further improved using the acyl amino acid ester of the present invention. These inorganic pigments may be used either singly or in combination of one or more thereof, depending on the use purpose.
When the inorganic pigments are incorporated into cosmetic compositions, one or more of these pigments are combined, if necessary or desired, and oily material(s), water-soluble material(s), surfactant(s), flavor(s), chemical(s) and the like for cosmetics are added thereto and dispersed therein. The role of the inorganic pigment in cosmetic compositions is great. A color pigment adjusts the color tone of a product, and a white pigment controls the color tone and also the hiding power. An extender pigment adjusts the color tone as a diluent, and also use properties (extensibility, adhesion), a gloss and the like of a product. Further, the extender pigment is also used to maintain the form of the product. A pearlescent pigment gives a product a glaze. Pigments having special functions have been developed relatively recently in order to increase use properties or a makeup effect as well as an ultraviolet ray-scattering effect upon incorporating the same into a product.
The size (particle size) of the powdery inorganic pigment to be contained in the inorganic pigment composition of the present invention is not particularly limited, and a size corresponding to each composition can be determined. The adjustment of the size to an appropriate value is not particularly limited. The adjustment of the size can be conducted before an inorganic pigment is incorporated as an ingredient (in advance) or during the starting materials of a desired composition are added and kneaded to prepare the compositon, as can be seen in production of a color pigment composition. Of course, it is also possible that the size is adjusted to some extent in advance and further adjusted, as required, in kneading the starting materials.
Next, the N-long-chain acyl neutral or acidic amino acid ester which is another essential ingredient of the inorganic pigment composition of the present invention will be described.
Such N-long-chain acyl neutral amino acid ester is exactly the same as the N-long-chain acyl neutral amino acid ester described earlier with respect to the first invention.
When preferable examples of the N-long-chain acyl neutral amino acid ester of the present invention are represented by a general formula, those represented by Formula (1) above can be mentioned.
Further, the N-long-chain acyl acidic amino acid diester is exactly the same as the N-long-chain acyl acidic amino acid diester described earlier with respect to the second invention.
These N-long-chain acyl amino acid esters are less irritative to the skin or the mucous membrane, and are excellent in feelings upon use such as extensibility on, adaptability with, and smoothness to, the skin. Accordingly, these are excellent when used as an oily material for cosmetics in particular. Especially, the N-long-chain acyl neutral amino acid ester is free from unpleasant oily feeling and stickiness peculiar to an oily material, and is excellent in a light feeling such as a clean or dry feeling. Thus, it is better than the N-long-chain acyl acidic amino acid diester when it is used in a cosmetic composition.
The simplest embodiment or mode of the inorganic pigment composition of the present invention is a mixture composed substantially of the powdery inorganic pigment and the N-long-chain acyl neutral amino acid ester or/and the N-long-chain acyl acidic amino acid diester, and it can as such be put into circulation. This is later incorporated into cosmetics, paints or the like as required.
The preparetion of such a mixture is not particularly limited, nor difficult to do. It can be conducted by an appropriate known method. The amount of a powdery inorganic pigment in the mixture of this embodiment is determined according to the intended use. The remainder is the N-long-chain acyl neutral amino acid ester or/and the N-long-chain acyl acidic amino acid diester.
It is also possible to form the inorganic pigment composition of the present invention by coating the N-long-chain acyl amino acid ester on the (particle) surface of the inorganic pigment, instead of preparing such a simple mixture.
The coating method is not particularly limited. The coating can be conducted by, for example, a method in which the N-long-chain acyl amino acid ester of the present invention is dissolved in a solvent such as ethanol or the like, the pigment is then dispersed therein, and the solvent is then distilled off through evaporation. When the coating is conducted to prepare the inorganic pigment composition of the present invention, the amount of the N-long-chain acyl amino acid ester is not particularly limited. It can usually be adjusted to from 1 to 5% by weight based on the inorganic pigment.
Further, the inorganic pigment and the N-long-chain acyl neutral amino acid ester or/and the N-long-chain acyl acidic amino acid diester can be used in the form of a composition of the foregoing mode (mixture and coated), or can be directly incorporated without having been formed into a composition of such mode in advance, to provide cosmetics, paints, ink and the like. The thus-prepared cosmetics and the like are of course a kind of the inorganic pigment composition of the present invention.
The amount of an inorganic pigment in the composition of this embodiment is determined according to the use of the composition. For example, in case of cosmetic compositions, it is ordinarily used in the range of from 0.01 to 90% by weight. The amount of the N-long-chain acyl amino acid ester of the present invention relative to the inorganic pigment is also determined according to the use of the composition. When it is used as a cosmetic compositions, it is usually (inorganic pigment)/(N-long-chain acyl amino acid ester)=100/0.1 to 1/100, and preferably 100/1 to 10/100. When the ratio of the N-long-chain acyl amino acid ester is low, satisfactory dispersibility of the inorganic pigment is not provided sometimes.
The inorganic pigment composition of the present invention in the mode of cosmetics or the like can be prepared by a conventional method including starting materials, except that the inorganic pigment and the N-long-chain acyl neutral amino acid ester or/and the N-long-chain acyl acidic amino acid diester (an embodiment (coating) where the latter is coated onto the particle suraces of the former is naturally included also) are incorporated in predetermined amounts into the other starting materials.
When the inorganic pigment composition of the present invention is used as a cosmetic composition, it can be one of various cosmetic compositions, such as cleansing cream, massage cream, cold cream, moisture cream, milky lotion, lotion, hand cream, foundation, lipstick, press powder, eye shadow, hair oil or cream in stick form, hair liquid, setting lotion, hair cream, hair lotion, hair mousse, anti-sunburn cream, anti-sunburn oil and the like. Further, the form is not particularly limited. Any form will do. Examples thereof include an emulsion form, a solution form, a soluble form, a powder dispersion form, a water-oil two-layer form, a water-oil-powder three-layer form and the like.
When an inorganic pigment composition of the present invention is prepared into a cosmetic composition, some other oily materials can optionally be incorporated unless the effects of the present invention are impaired. Such oily materials are exactly the same as the other oily materials which can be incorporated into a cosmetic composition of the first invention, as has been described earlier.
Further, one or more of various surfactants can also be added to the cosmetic composition according to the present invention unless the effects of the present invention are impaired. Such surfactants are exactly the same as those which can be incorporated into the cosmetic composition of the first invention, as has been described earlier.
Still further, in addition to those components mentioned above, various additives which are ordinarily used in a cosmetic composition can also be added to the cosmetic compositons according to the present invention. Such various additives are exactly the same as those as described earlier, which can be incorporated into the cosmetic composition of the first invention.
The invention will be illustrated more specifically by referring to Examples including Synthesis Examples, Reference Synthesis Examples, Examination Examples and Formulation Examples of cosmetic compositions. However, the invention is not limited to these Examples.